Methods and systems for providing an asymmetric Ethernet service

ABSTRACT

Methods and systems for providing asymmetric Ethernet service are disclosed. An example method to provide asymmetric Ethernet service to a subscriber includes communicating at least a first portion of a subscriber data communication via a first asymmetric Ethernet connection between a first asymmetric Ethernet modem at a point of service and a second asymmetric Ethernet modem at a service provider location, communicating at least a second portion of the subscriber data communication via a second asymmetric Ethernet connection between a third asymmetric Ethernet modem at the point of service and a fourth asymmetric Ethernet modem at the service provider location, wherein the first and second asymmetric Ethernet connections provide a faster aggregated download bandwidth than an aggregated upload bandwidth to provide an asymmetric Ethernet connection between the point of service and the service provider location, and aggregating the first and second portions of the subscriber data communication for transmission to an Ethernet data network.

RELATED APPLICATIONS

This patent arises from a continuation of U.S. patent application Ser.No. 10/636,005, filed Aug. 7, 2003, now U.S. Pat. No. 7,779,162, issuedAug. 17, 2010, the entirety of which is hereby incorporated byreference.

TECHNICAL FIELD

The present invention is related to Ethernet communications. Moreparticularly, the present invention is related to providing anasymmetric Ethernet service from a service provider network to asubscriber point of service.

BACKGROUND

Ethernet communications are a popular data network protocol used tocarry frames of data. Ethernet communications are often used withinlocal area networks to carry data between nearby computers as well aswithin wide area networks where the Ethernet may be carried throughlower layer connections such as an asynchronous transfer mode (“ATM”)link. Ethernet communications allow for the transfer between end pointsof higher layer data packets such as Internet Protocol packets that aredestined for a remote location such as a domain of the global Internet.The original Ethernet standards related to a protocol for accessing ashared communication medium. Over time this has evolved to a suite ofprotocols that are commonly used on symmetric point-to-point linksbetween Ethernet switching devices. Ethernet protocols can also beencapsulated and transported over other protocols, e.g., Ethernet overATM per RFC 1483.

Typically, an Ethernet network includes many closely located devicesinterconnected via the Ethernet protocol to form a local area network.Because the devices are located closely, there is a direct Ethernetconnection between the devices since the distances are not greater thanthat possible over a direct Ethernet connection. However, somesituations call for a node of an Ethernet network to be located remotelyfrom the Ethernet network itself such that the distance is too great fora direct Ethernet connection to be utilized.

Ethernet service has been provided to certain customers having a pointof service that is remote from the Ethernet network such that a directEthernet connection cannot be utilized. This Ethernet service issymmetrical and provides a relatively high bandwidth to subscribers inboth the upload and download directions, but because this data transferis symmetrical it requires a relatively high amount of bandwidth of aservice provider network interconnecting the point of service to theEthernet network. Thus, this symmetrical Ethernet service is not aneconomical option for many subscribers.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a high level view of an asymmetric Ethernet service from anEthernet network to a point of service of a subscriber according to anembodiment of the present invention.

FIG. 2 is a diagram of the connectivity of devices to aggregate Ethernetlinks, which may be used in embodiments of the present invention.

DETAILED DESCRIPTION

Some examples of the present invention described herein provide for anasymmetric Ethernet service to be provided between an Ethernet networkand a point of service for a subscriber. The asymmetric Ethernet serviceprovides for effective data transfer rates that are greater in onedirection of transfer than the other, thereby freeing the data networkbetween the point of service and the Ethernet network from providing afull speed data transfer rate in both directions. The asymmetricEthernet service may be provided by including the point of service atthe network interface device outside the premises of the subscriberwhere the endpoint communications device is maintained as part of aservice provider network to eliminate the requirement of additionalcommunications devices such as DSL or cable data modems within thepremises of the subscriber. Alternatively, the asymmetric Ethernetservice may be provided through communications devices such as DSL orcable modems of the subscriber rather than including them as endpointdevices of the service provider network.

Some example systems and methods address the issues described above andothers by providing an asymmetrical Ethernet service to a point ofservice for subscribers. Thus, the subscribers may connect theirEthernet devices such as routers and/or computers to the asymmetricEthernet service which provides a difference in the upload and downloaddata transfer speeds when communicating with the remote Ethernetnetwork.

Some example methods of providing asymmetric Ethernet service aredescribed, including providing an Ethernet network remote from a pointof service and in communication with the point of service. The examplemethods further involve establishing an asymmetric Ethernetcommunication between the remote Ethernet network and the point ofservice to allow access to the asymmetric Ethernet service by asubscriber. Example systems for providing asymmetric Ethernet serviceare also described, which include an Ethernet network including anEthernet port and includes a point of service located remotely from theEthernet port of the Ethernet network. An Ethernet communicationsconnection exists between the subscriber point of service and theEthernet port of the Ethernet network. The Ethernet communicationsconnection provides for an upload speed from the subscriber point ofservice to the Ethernet port of the Ethernet network that is a differentspeed than a download speed from the Ethernet port of the Ethernetnetwork to the point of service.

In some examples, a system for providing asymmetric Ethernet service toa network device of a subscriber includes an Ethernet network includingan Ethernet port and includes a point of service located remotely fromthe Ethernet network. An Ethernet connection exists between the point ofservice and the Ethernet port of the Ethernet network. The Ethernetconnection provides for an upload speed from the point of service to theEthernet port of the Ethernet network that is a different speed than adownload speed from the Ethernet port of the Ethernet network to thepoint of service. An Ethernet connection also exists between the pointof service and a network device of the subscriber.

FIG. 1 shows a high level view of an asymmetric Ethernet service. AnEthernet network 102 provides Ethernet data services for subscribers,such as providing access to LAN resources such as email and file serversand/or access to a downstream Internet Service Provider (“ISP”). Aservice provider may provide the connectivity between the Ethernetnetwork 102 and the point of service where the subscriber gains accessto the Ethernet network at a device 122 of the subscriber such as anetwork interface card (“NIC”) equipped computer, router, or otherEthernet capable device. The service provider, or another serviceprovider, may also provide access to the public switched telephonenetwork (“PSTN”) 104 for subscribers. As shown in FIG. 1, the Ethernetnetwork access may be distributed to the subscriber from the Ethernetnetwork 102 in various ways. For example, ADSL modem 106 or set ofmodems contained within a DSL access multiplexer (“DSLAM”) or a serviceprovider may be used to transport the Ethernet data communicationsbetween a central office (“CO”) of the service provider and out to thelocation of the subscriber. The ADSL communications carrying theEthernet data are received at a service point by another ADSL modem 108or set of modems where the ADSL data communications are then convertedback to Ethernet layer communications for access by the subscriber atthe point of service.

The Ethernet communications extend over communication lines 112 to thepoint of service, such as the NIC 122. These Ethernet communications aremade asymmetric by the ADSL modems 106 and 108 providing the asymmetrybetween the upload and download data transfer rates while carrying theEthernet data frames. The upload speed may be faster than the downloadspeed or the download speed may be faster than the upload speed. Forexample, ADSL modems 106 may be type ATU-C and ADSL modems 108 may beATU-R so that the download for the subscriber is faster than the upload.Alternatively, the ADSL modems 106 may be type ATU-R while ADSL modems108 may be ATU-C so that the upload for the subscriber is faster thanthe download.

Providing an upload speed faster than a download speed between the ADSLmodems 106 and 108 may not be permitted under a regulatory scheme wherecopper communications extend from the ADSL modem 106 back to the network102 and where the upload speed refers to an upload from the subscriberto the service provider network. However, the ADSL modem 106 may bepositioned away from a CO to a point that is closer to the point ofservice where the ADSL modem 108 is positioned. The ADSL modem 108 maybe positioned at the point of service where located within thesubscriber's premises, or alternatively very closely to the point ofservice, such as at a street corner out from the location of thesubscriber. Thus, the distance the Ethernet link must travel from theADSL modem 108 to the point of service for access by the subscriber maybe minimized. Communications between the location of the ADSL modem 106and the network 102 may then occur over fiber to avoid the faster uploadspeeds from creating copper networking issues.

The asymmetric Ethernet service extends from an Ethernet port of theADSL modem 108 over communications line 112 into the device 122. Thus,the subscriber can access the Ethernet network over the asymmetricEthernet connection at the device 122. The device 122 appears as a nodeon the Ethernet network 102 even though the device 122 is locatedremotely from the Ethernet network 102 because the Ethernet frames thatare exchanged between the Ethernet network 102 and the device 122 arebeing carried by the ADSL connectivity.

The asymmetric Ethernet service may also utilize aggregated Ethernetconnections so as to increase the bandwidths of the data transferdirections while maintaining the asymmetry. For example, an aggregatordevice 126 such as an Ethernet switch may be positioned between theDSLAM containing modems 106 and the downstream link to the Ethernetnetwork 102. The aggregator device 126 aggregates the communications ofmultiple (1-N) ADSL modems 106 that are in communication with multiple(1-N) ADSL modems 108. The multiple ADSL modems 108 are then aggregatedby an aggregator device 124 located between the modems 108 and the pointof service. Thus, the single Ethernet link 112 may benefit from thebandwidth of multiple ADSL modem connections to increase the effectivebandwidth of the asymmetric Ethernet service being provided to thesubscriber. The aggregation of Ethernet links is described below in moredetail with reference to FIG. 2.

The asymmetric Ethernet service shown in FIG. 1 may also co-exist withother conventional services such as plain old telephone service(“POTS”). The DSLAM housing the ADSL modems 106 provides a splitterfunction to interconnect the link back to the Ethernet network 102 withthe ADSL modems 106 for data communications while interconnecting voicelinks from subscriber POTS devices 118 to the PSTN 104. The voice linksare passed through a filter-splitter, such as all the service pointwhere the modems 108 are located and also at the splitter function ofthe DSLAM so that the copper line pairs between the ADSL modems 108 andADSL modems 106 may carry both the voice signals and the data signalswhile preventing the data signaling from being heard by the POTSdevices. The filtered voice lines 110 extend to the POTS devices 118.

As shown in FIG. 2, the Ethernet communications of an Ethernet link suchas the Ethernet link to the point of service may be transferred bymultiple communications devices 206, 208 such as DSL modems 106 thatcommunicate with distant multiple communications devices 210, 212 suchas DSL modems 108. Where the Ethernet service is asymmetric, the uploadspeed differs from the download speed for the communication devices 206,208, 210, and 212.

The subscriber has a network device 202 that utilizes Ethernetcommunications, such as a router linked to a personal computer or suchas a NIC of the personal computer. The Ethernet communications areexchanged between the network device 202 and an aggregator device, suchas an Ethernet switch 204. The Ethernet switch 204 then communicateswith the two communications devices 206, 208 using Ethernetcommunications and aggregates the two devices 206, 208 for use by thenetwork device 202. The Ethernet switch 204 may aggregate communicationswith the two devices 206, 208 in accordance with the link aggregationstandard IEEE 802.1ad.

The communications devices 206, 208 then exchange communications withthe communications devices 210, 212 over the copper lines between thetwo sets of devices. This exchange is asymmetric when providing theasymmetric Ethernet service through application of the asymmetriccommunications devices on both ends of the connection. Thecommunications devices 210, 212 also communicate with an Ethernet switch214 that aggregates the communications of the communications devices210, 212 when exchanging communications with the Ethernet network andother downstream devices such as an ATM switch 216 or broadband servicegateway (“BSG”) 218. The Ethernet switching that provides for theaggregation of communication devices may alternatively be incorporatedinto the BSG 218 rather than utilizing an external Ethernet switch 214.The data communications from the communications devices 210, 212 may beexchanged with the Ethernet switch 214 by a direct Ethernet interfacefor a DSLAM, by ATM interfaces through the ATM switch 216 (e.g.,Ethernet over ATM encapsulation), or by interfaces from the BSG 218(e.g., Ethernet, ATM, or Ethernet encapsulated over an Internet Protocolinterface).

To optimize the aggregated communications devices, the aggregatordevices such as Ethernet switches 204, 214 may perform rate shapingand/or load balancing. The aggregator devices may perform rate shapingby directing frames of data according to the upload speed of thecommunications devices being aggregated by the aggregator device. Thus,the aggregator device 204, 214 may store in memory the relative uploadspeed differential between the two communications devices connected tothe ports of the aggregator device. For example, with ADSL thedifferential may be defined as 8 megabits per second upload for onecommunication device and 1.5 megabits per second upload for the othercommunication device, which results in a differential factor of 5.3. Theaggregator device may then channel every sixth frame to thecommunications device with the slow upload speed while the fivepreceding frames are channeled to the communications device with thefast upload speed.

In addition to rate shaping, the aggregator device may load balancebetween the communications devices being aggregated. The aggregatordevice communicates status information with the communications devicesto detect the amount of data that a communications device has queued totransfer. If one of the communications devices has overly filled itsqueue relative to the other communications device, such as due to frameretransmissions or other similar reasons, then more frames aretemporarily directed to the other communications device until therelative loads of each communications device have become balanced.

While the discussion above has described the communications devices forproviding the asymmetric Ethernet service as ADSL modems, it will beappreciated that other types of communications devices that haveasymmetric data transfer rates may be used as well. Furthermore, whilethe aggregator device has been described as an Ethernet switch, it willbe appreciated that other types of aggregator devices may be used aswell, such as routers that perform aggregation at the Internet Protocollevel as opposed to the Ethernet level. Such a router may be optimizedto rate shape and load balance as discussed above, such as by modifyingthe equal cost multiple paths (“ECMP”) code to account for thedifferential in upload speeds of the communications devices that areattached.

As discussed above, the subscriber of the asymmetric Ethernet service isprovided an Ethernet connection at the point of service. The Ethernetservice provided to the subscriber at the point of service is madeasymmetric so that the effective upload and downloads speeds availableto the subscriber and that are supported in the service provider networkdiffer between the Ethernet network and the point of service.

Although the present invention has been described in connection withvarious illustrative embodiments, those of ordinary skill in the artwill understand that many modifications can be made thereto within thescope of the claims that follow. Accordingly, it is not intended thatthe scope of the invention in any way be limited by the abovedescription, but instead be determined entirely by reference to theclaims that follow.

What is claimed is:
 1. A method to provide asymmetric Ethernet service,comprising: receiving a subscriber data communication at an aggregatorlocated at a point of service; communicating at least a first portion ofthe subscriber data communication via a first asymmetric Ethernetconnection between a first asymmetric Ethernet modem at the point ofservice and a second asymmetric Ethernet modem at a service providerlocation; communicating at least a second portion of the subscriber datacommunication via a second asymmetric Ethernet connection between athird asymmetric Ethernet modem at the point of service and a fourthasymmetric Ethernet modem at the service provider location, wherein thefirst and second asymmetric Ethernet connections provide a fasteraggregated download bandwidth than an aggregated upload bandwidth toprovide an aggregated asymmetric Ethernet connection between the pointof service and the service provider location, the first and secondportions of the subscriber data communication originating from a samedevice; and thereafter aggregating the first and second portions of thesubscriber data communication for transmission to an Ethernet datanetwork.
 2. The method as defined in claim 1, wherein the aggregateddownload bandwidth of the first and second Ethernet connections ishigher than a first download bandwidth of the first asymmetric Ethernetconnection and higher than a second download bandwidth of the secondasymmetric Ethernet connection.
 3. The method as defined in claim 1,wherein the aggregated upload bandwidth of the first and second Ethernetconnections is higher than a first upload bandwidth of the firstasymmetric Ethernet connection and higher than a second upload bandwidthof the second asymmetric Ethernet connection.
 4. The method as definedin claim 1, further comprising: communicating at least a third portionof the subscriber data communication via the first asymmetric Ethernetconnection; communicating at least a fourth portion of the subscriberdata communication via the second asymmetric Ethernet connection; andaggregating the third and fourth portions of the subscriber datacommunication for transmission to a subscriber at the point of service.5. A system to provide asymmetric Ethernet service, comprising: a firstasymmetric Ethernet connection to communicate data between a firstasymmetric Ethernet modem at a point of service and a second asymmetricEthernet modem at a service provider location; a second asymmetricEthernet connection to communicate data between a third asymmetricEthernet modem at the point of service and a fourth asymmetric Ethernetmodem at the service provider location; a first aggregator to direct afirst portion of an upload subscriber data communication over the firstasymmetric Ethernet connection, the first aggregator to direct a secondportion of the upload subscriber data communication over the secondasymmetric Ethernet connection, the first and second portions of theupload subscriber data communication originating from a same device, andthe first aggregator to aggregate first and second portions of adownload subscriber data communication from respective ones of the firstand second asymmetric Ethernet connections; and a second aggregator todirect the first portion of the download subscriber data communicationto the first asymmetric Ethernet connection, the second aggregator todirect the second portion of the download subscriber data communicationto the second asymmetric Ethernet connection, and the second aggregatorto aggregate the first and second portions of the upload subscriber datacommunication from respective ones of the first and second asymmetricEthernet connections.
 6. The system as defined in claim 5, wherein thesecond aggregator is to transmit an aggregated upload subscriber datacommunication to an Ethernet data network.
 7. The system as defined inclaim 6, wherein the second aggregator is to transmit the aggregatedupload subscriber data communication via a third connection having anupload bandwidth higher than the first asymmetric Ethernet connectionand higher than the second asymmetric Ethernet connection.
 8. The systemas defined in claim 5, wherein the first aggregator is to transmit anaggregated download subscriber data communication to a subscriber. 9.The system as defined in claim 8, wherein the second aggregator is totransmit the aggregated upload subscriber data communication via a thirdconnection having a higher download bandwidth than the first asymmetricEthernet connection and the second asymmetric Ethernet connection. 10.The system as defined in claim 5, wherein at least one of the first,second, third, and fourth modems is an asynchronous digital subscriberline modem.